Quote Originally Posted by green91
For a vacuum booster to somehow make a pedal softer, you would have to increase the amount of vacuum going to it. A vacuum leak, hole in diaphragm etc would make your brake pedal harder due to lack of vacuum assist. I cannot think of a way that a bad booster would make your pedal softer.
If there is less pressure in the line the pedal travels easier.

Either way, if this is the case you should hear a suction type noise when you apply the pedal. If not then it is something else.